Time control contactor



Dec. 27, 1938. o. J. RYDER T IME CONTROL CONTACTOR Filed Sept. 6, 1934 2Sheets-Sheet l INVENTOR. 077')? J Fig/den ATTORNEY5.

Dec. 27, 1938. Q J RY ER 2,141,561

TIME CONTROL CONTAGTOR Filed Sept. 6, 1934 2. Sheets-Sheet 2 INVENTOR.Orz'n J7 Ryder A TTORNEYS.

Patented Dec. 27, 1938 UNITED STATES PATENT OFFICE TIME CONTROLCONTACTOR of Delaware Application September 6, 1934, Serial No. 742,921

Claims.

My invention relates to control relays and particularly to a controlrelay regulatable to control the time of flow of current through weldingelectrodes.

5 Difficulty has been experienced in the welding art when relying uponthe personal equation of an operator to effect the sequence in operationof a welding gun. That is to say, in operating the trigger of the gun inproper timed movement to efiect the movement of the welding electrodesto clamped position with the work to be welded and for actuating a relayand retaining the relay closed for the proper length of time, terminatedby the release of the trigger which de-energizes the relay and effectsthe release of the electrodes. It is very evident that at differenttimes with the same operator, and through the employment of variousoperators, different welds will result. If the trigger is moved toorapidly the relay may actually contact to cause a flow of currentthrough the electrodes before the electrodes actually clamp the work. Onthe other hand, if the trigger is not retained the proper length of timeto maintain the relay closed, suflicient cur- $115 rent will not flowthrough the material to effect a proper weld. Further, if the trigger isretained in switch-closed position too long a time, too great a flow ofcurrent through the electrodes will occur, causing a burning of themetal.

,i -i The present invention eliminates the personal equation abovepointed out which varies the quality of the weld obtained when anoperator controls the actuation of the welding gun. By the employment ofa relay which times the flow 3 of current not only is the proper weldobtained but it was found that the time for making such weld can bematerially decreased. This is made possible in View of the fact thatsince the time is accurately controlled a greater flow of current to canbe employed for producing the weld. In view of the personal time elementit was the practice in the past to reduce the current as much aspossible to permit a greater variation in the time the current wasflowing.

A3 The relay embodies a solenoid and a plurality of movable contactelements forming a circuit closing device which was actuated thereby.When a three phase circuit is utilized, three sets of contacts areemployed and actuated simulta- :3") neously. The solenoid is providedwith a movable armature which is connected to the circuit closing devicethrough an adjustable cam element. The cam engages a projecting plungerof the device and by adjusting the position of the .55 cam to regulatethe length of engagement of the cam surface with the plunger, the timeinterval the contacts are closed may be lengthened or shortened.

After the plunger passes over the face of the cam, the contacts arereleased even though the solenoid may remain energized to retain thearmature in moved position when the operator retains the switch, foreffecting actuation of the solenoid, closed. Suitable means may beemplayed to assure the operation of the electrodes into engagement withthe work before the solenoid is actuated. The one herein illustratedembodies the operation of the switch for closing the current whichenergizes the solenoids, by the air y pressure built up in the electrodeactuating cylinder after the piston thereof has been moved to efiect theengagement of the electrodes with the work. Other well known forms couldbe employed, such as providing a cylinder and bleeding valve forcontrolling the time operation of the trigger of the gun.

Accordingly, the main objects of my invention are: to provide a controlrelay having means for regulating the time interval during which thecontacts thereof remain closed; to employ a time adjustable contactrelay by which the time of flow of current through electrodes isaccurately controlled; to provide a constant time interval in which thecontacts of a relay remain closed so that a greater flow of current maybe employed to decrease the time required to eiTect a welding operation;to provide means for actuating electrodes into work-engaged positionbefore the actuation of a control relay to pass current therethroughand, in general, to provide a time adjustable control relay forregulating the time of flow of current through welding electrodes whichis simple in construction, positive in operation and economical ofmanufacture.

Other objects and features of novelty of my invention will be eitherspecifically pointed out or will become apparent when referring, for abetter understanding of my invention, to the following description takenin conjunction with the accompanying drawings, wherein:

Figure l is a view in elevation of a control relay embodying features ofmy invention,

Figure 2 is a side view of the structure illustrated in Fig. 1,

Figure 3 is an enlarged sectional View of the structure illustrated inFig. 2, taken on the line 3-3 thereof,

Figure 4 is a view of the structure illustrated in Fig. 3, taken on theline 4-4 thereof,

Figure 5 is a view of the welding mechanism and relay in connectedrelation, and

Figure 6 is an enlarged view of a portion of the welding mechanismillustrated in Fig. 5, showing a modified form thereof.

Referring to Fig. 1, I have illustrated a control relay ID as comprisinga solenoid having a movable armature l2 pivoted on spaced brackets l3.The .armature is provided with an extending arm l4 upon which acam-supporting bracket |5 is secured by suitable bolts I6. The arm |4also carries a bridging contact element H which bridges a pair ofcontacts 8 when the solenoid is de-energized and. which bridges a pairof contacts l9 when the armature is drawn within the solenoids. Asupporting bar 2| is aligned with the pivot l3 of the armature |2 beingpivotally retained on suitable brackets 22. The bar carries and actuatesa plurality of contacts 23 into engagement with a plurality ofstationary contacts 20 to close circuits through terminals 24 and 25.Suitable arc suppressing chutes 26 are disposed over the pairs ofcontacts in a conventional manner. From Fig. 3 it will be noted that thecontact supporting bar 2| has a metal base 43 over which a tube 44 ofinsulating material is disposed. In this manner, the contacts supportedon the bar are insulated from each other.

For interconnecting the armature |2 with the contact supporting bar 2|,I have provided a unique time controlling mechanism illustrated enlargedin Figs. 3 and 4 which will now be described. As pointed out above, thearmature arm l4 supports a cam bracket l5 upon which a cam plate 21 isretained by a bolt 28 for pivotal movement about the bolt axis.Preferably, an arouate surface or cam face 29 is provided on the camplate 21 struck about the axis of the bolt 28. The surface 29 acts asthe cam portion of the plate and may be angularly disposed relative tothe bolt 28 through the adjustment of a screw 3| clamped in adjustedposition by a nut 32. The contact supporting bar 2| is provided with anarm 33 upon which is mounted an L-shaped camengaging element, orplunger, 34 for pivotal movement about a pin 35 carried by a lug 36 onthe arm 33. An aperture 31 is provided in the element 34 through which abolt 38 extends which is screwed into the body portion of the arm 33. Aspring 39 is disposed about the body of the bolt and urges the element34 forwardly to be in position to be engaged by the arm 33.

When the solenoid II is energized, the armature I2 is drawn therein tohave the lower portion of the arm l4 move in a clockwise direction whenviewed as illustrated in Fig. 2. That is to say, moves outwardly fromthe drawings when viewed as illustrated in Fig. 3. The movement of thearm M in this manner causes the camming surface 29 of the cam plate 2'!to engage the end 30 of the cam engaging element 34 to cause the elementto move therewith to thereby rotate the contact supporting bar 2| tocause the contacts 23 to move into engagement with the contacts 20.Further movement of the plate 21 causes the camming surface 29 to moveacross the point 30 of the cam engaging element 34, which will pivotabout the pin 35 against the pressure of the spring 39. After the point30 passes over the cam face 29 upon the continued movement of thearmature and plate 21, the element 34 is released and the contacts 23will move to open position. This opening movement is effected by aspring 4| assisting springs 42 of the contacts. When the time thecontacts 23 remain closed is to be shortened it is only necessary toloosen the nut 32 and to adjust the screw 3| to rotate the plate 21counterclockwise about the center of the bolt 28 to reduce the length ofthe available face portion 29 of the cam and thereby reduce the time thecontacts are retained in closed position. When the solenoid II isde-energized the armature 2 is returned to open position, the plate 21being pivoted around the center of the bolt 28 until such times as thecam surface 29 clears the end 30 of the cam-engaging element 34whereupon the plate will move in a clockwise direction about the bolt 23into engagement with the screw 3|, as illustrated in Fig. 4. The contactrelay thus constructed is capable of being regulated to adjust the timethe contacts are retained in closed position and, while simple inconstruction, is rigid and positive of operation.

Referring to Fig. 5, I have illustrated the contactors l8 as beinghooked up in a circuit with a transformer 45 and a welding gun 46. Theenergizing circuit 4! for the solenoid passes through a switch 48 in thewelding gun 46 where the circuit is completed and broken. A three phasealternating current circuit (not shown) is connected to the terminals 25and after passing through the relay is connected by the contacts 24 andthe three phase circuit 49 to the transformer 45. The transformerchanges the current from the high voltage low current supply to a lowvoltage high current supply for welding purposes. Suitable conductors 5|connect the circuit from the transformer 45 to a stationary electrode 52to a movable electrode 53 of the gun 46. The electrode 53 is urged andmoved toward the electrode 52 by a piston 54 carried by a cylinder 55 inthe welding gun. A suitable supply line 56 conducts a fluid, preferablyair, to the gun, the passage to the cylinder 55 being interrupted by acontrol plunger 51 which is actuated by a trigger 58. The trigger 58 isalso in a position to actuate a plunger 59 on the switch 48.

When operating the gun, the electrodes 52 and 53 are positioned tobridge the elements to be Welded whereupon the trigger 58 is actuated topermit a flow of fluid into the cylinder 55. The fluid actuates theplunger 54 forwardly to move the electrode 53 toward the electrode 52and to clamp the work therebetween. Upon further movement, the triggerengages and actuates the plunger 59 to close the circuit 41 to therebyenergize the solenoid H for actuating the armature l2 and the contacts23 to closed position. This completes the circuit 49 to the transformer45 to energize the transformer and pass current through the circuit 5|and the electrodes to efiect the welding operation.

The time the current is flowing through the metal to be welded iscontrolled by the setting of the cam plate 21 which regulates the timewhich the contact supporting bar 2| is held thereby after which thecontacts 23 move to open position during the final forward movement ofthe armature l2 toward the solenoid II. In this manner, the current tothe electrodes 52 and 33 is shut off independent of the release of thetrigger 58 so that a constant timing of current flow results for eachweld. The trigger 58 is then released, opening the circuit of thesolenoid II and cutting off the now of fluid to the cylinder 55. Thefluid in the cylinder passes out through the vent 60 as a spring 6|,disposed forwardly of the piston, returns the piston and electrode 53 totheir original positions.

As has been pointed out hereinabove, there is a possibility that thetrigger 58 will be operated so fast that the solenoid I I will beactuated to move the armature I2 before the Welding electrode 53 hasbeen moved to clamped engagement with the Work and the electrode 52.When this occurs, the Welding takes place before the actual clamping ofthe element and improper welds naturally result.

Referring to Fig. 6, I have illustrated a switch 62 which may beemployed in place of the switch 48 illustrated in Fig. 5. In thisconstruction, the circuit 41 is directly connected to a stationarycontact 63 and a movable contact 64 forming part of the switch 62. Aplunger 65 is disposed in an aperture 66 which communicates with thecylinder 55. The plunger has a spring 61 thereon which urges it towardthe interior of the cylinder. Suitable washers 68, on the end of theplunger, prevent the movement of the plunger out of the aperture.

When the trigger is operated, air flowing into the cylinder 55, willmove the piston 54 to cause the electrode 53 to move into clampedrelation with the work to be welded and the electrode 52. Thereuponpressure will build up within the cylinder to cause the operation of theplunger 65 which will move the contact 64 into engagement with thecontact 63 to energize the solenoid I I to efiect the weld in the samemanner as above explained. Upon the release of the trigger 58, thecontact 64 will move away from the contact 63 as the piston 54 isreturned to its original position and thereby de-energize the solenoidII.

In this manner, irrespective of the speed of operation of the trigger58, the sequence in operation will always remain the same. In eitherinstance, the timing of the flow of current through the Weld ispositively and accurately controlled, for which reason a greater flow ofcurrent may be employed to efiect the welding operation, which furtherreduces the time required to effect the weld.

While I have described and illustrated several embodiments of myinvention, it will be apparent to those skilled in the art that variouschanges, omissions, additions and substitutions may be made thereinwithout departing from the spirit and scope of my invention, as setforth in the accompanying claims.

I claim as my invention:

1. A contact relay including, in combination, a circuit-closing device,a movable member, a cam carried by said member, means carried by saiddevice engageable by said cam when the member is moved to operate saiddevice and retain the circuit closed while the cam passes over saidengageable means, and means for adjusting said cam to regulate the timesaid means is in engagement therewith.

2. A contact relay including, in combination, a circuit-closing device,a movable member, a cam carried by said member, a spring pressed plungercarried by said device in the path of movement of said cam, and meansfor adjusting said cam to regulate the time of engagement of saidplunger therewith during its movement.

3. A contact relay including, in combination,

a device for closing a circuit through welding electrodes, a movablemember, means interconnecting the member and device for completing saidcircuit during a portion of the movement of the member and to releasesaid device before movement of said member is completed, and means forvarying the length of time the circuit is completed during the movementof said member.

4. A contact making and breaking device including, in combination, amovable current carrying member, an actuating member, a cam car ried byone of said members free to pivot in one direction, means restrainingsaid cam against pivotal movement in the opposite direction, meanscarried by said other member engageable with said cam and movabletherewith when said actuating member is moved to move the currentcarrying member into circuit closed position, and means permitting saidlast named means to be released from said cam thereafter and during themovement of said actuating member.

5. A contact making and breaking device including, in combination, amovable current carrying member, an actuating member, a cam carried byone of said members free to pivot in one direction, means restrainingsaid cam against pivotal movement in the opposite direction, meanscarried by said other member engageable with said cam and movabletherewith when said actuating member is moved to move the currentcarrying member into circuit closed position, and means permitting saidlast named means to be released from said cam thereafter and during themovement of said actuating member, said means for restraining said camagainst movement being adjustable to vary the time of engagement withsaid engageable means.

ORIN J. RYDER.

